Electrically operated hospital bed



6 Sheets-Sheet 1 IN V EN TOR. %W

ATTORNEYS.

BY I? 7 Nov. 9, 1965 s. N. MANN ELECTRICALLY OPERATED HOSPITAL BED Filed May 16. 1961 Nov. 9, 1965 s. N. MANN 3,216,026

ELECTRICALLY OPERATED HOSPITAL BED Filed May 16, 1961 6 Sheets-Sheet 2 n mm [I Q [I INVENTOR.

ATTORNEYS.

Nov. 9, 1965 s. N. MANN ELECTRICALLY OPERATED HOSPITAL BED 6 Sheets-Sheet 3 Filed May 16, 1961 INVENTOR. Mm

ATTORNEYS Nov. 9, 1965 s. N. MANN 3,216,026

ELECTRICALLY OPERATED HOSPITAL BED Filed May 16. 1961 6 Sheets-Sheet 4 I i I ATTORNEYS.

Nov. 9, 1965 s. N. MANN ELECTRICALLY OPERATED HOSPITAL BED 6 Sheets-Sheet 5 Filed y 16, 1961 ATTORNEYS.

l v i. sh fill Il g? Nov. 9, 1965 s. N. MANN ELECTRIGALLY OPERA TED HOSPITAL BED 6 Sheets-Sheet 6 Filed May 16. 1961 INVENTOR. JW BY 26 ATTORNEYS.

\WQM mQQR llllllllllll United States Patent 3,216,026 ELECTRICALLY OPERATED HOSPITAL BED Stuart N. Mann, Derby, N.Y., assignor to Hard Manufacturing Company, Buffalo, N.Y. Filed May 16, 1961, Ser. No. 110,402 11 Claims. (Cl. -66) This invention relates to hospital beds, parts of which may be moved into various positions by power-operated means under control of the patient or a nurse or other attendant to move the parts of the bed supporting the patient into various positions.

One of the objects of this invention is to provide a bed of this type with. a plurality of independent drive shafts which are arranged in parallel relation to the bed and which remain in parallel position during all adjustments of the bed parts, so as to eliminate the use of universal joints in these shafts. It is also an object to provide a structure by means of which the strains resulting from the adjustment of the bed parts are localized to avoid transmission of these strains to other parts of the bed.

Another object is to provide mechanism for moving various parts of the bed into different positions and which are constructed so that in the event of a break of any of the mechanism controlling the positions of the bed, the bed parts will be held in approximately the same position which they occupied before the break so that no falling of any part of the bed or shock to the patient will occur.

It is also an object of this invention to provide a bed in which the switch controlled by the patient is operated at a low voltage so that even if the patient actuates the switch in an oxygen tent, no explosion will result.

Another object of this invention is to provide a bed which is operated by power means to locate parts of the bed in different positions for the convenience of the patient and which is also provided with means for readily shifting the positions of the bed parts manually in case of failure of the power means.

A further object is to provide a bed of this type in which the various parts are so mounted that they can be easily assembled and in which the parts are also readily accessible so as to facilitate repairs and maintenance of the bed.

In the accompanying drawings:

FIG. 1 is a side elevation of a bed embodying my invention.

FIG. 2 is a sectional plan View thereof on line 2-2, FIG. 1.

FIG. 3 is a fragmentary, sectional view thereof on line 3-3, FIG. 2, on a larger scale.

FIG. 4 is a fragmentary, sectional view thereof on line 4-4, FIG. 2.

FIG. 5 is a fragmentary, sectional plan view of the structure shown in FIG. 4 with parts broken away.

FIG. 6 is a transverse, sectional elevation thereof on line 6-6, FIG. 2.

FIG. 7 is a fragmentary, sectional plan view thereof on line 7-7, FIG. 6.

FIG. 8 is a fragmentary, sectional elevation thereof on an enlarged scale on line 8-8, FIG. 7.

FIG. 9 is a fragmentary, sectional elevation similar to FIG. 8 with parts in different positions with part of the housing broken away.

FIGS. 10 and 11 are fragmentary, transverse sectional views thereof on lines 10-10 and 11-11 respectively, FIG. 9.

FIG. 2 is a fragmentary section taken on line 12, FIG. 10.

FIG. 13 is a face view of a switch or control member for use by a patient in controlling the various positions of the bed parts.

FIG. 14 is a face view of a switch or control device of modified construction.

FIG. 15 is a diagram of electrical circuits for use in connection with a hand control or switch member as shown in FIG. 13.

FIG. 16 is a diagram of electrical circuits for use with a switch member as shown in FIG. 14.

The bed frame to which my improvements are applied may be of any suitable or usual construction, that shown by way of example including end frame members 18 detachably connected with side rails or bars 19 on which a spring or mattress supporting frame of any desired type may be mounted. The end frames include legs 20 of tubular form, those shown being square in cross section and having inner, tubular leg members 21 telescopically arranged therein so that by relative movement of the inner tubular members 21 with reference to the outer members 20, the height of the bed frame above the floor may be varied. The two side rails are rigidly connected by a plurality of cross members 23 welded or otherwise secured to the side rails. The means for changing the height of the bed springs relatively to the bed frame may be effected by any suitable mechanism, parts of which are arranged within the end frame members themselves, such parts, for example, may be disclosed in copending application No. 820,637, now Patent No. 3,050,744, filed June 16, 1959 jointly by myself and A. Boyd Doty and assigned to Hard Manufacturing Company. Consequently it is not deemed necessary to show such parts of the raising and lowering mechanism in this application. The raising and lowering mechanisms in the bed ends have short shafts 24 extending outwardly therefrom and which are turned to actuate the mechanisms therein. These mechanisms are identical and consequently only the connections for the head end of the bed are described.

The shaft 24 is arranged in a sleeve 25 and rotary motion is applied to the shaft 24 by means of a driving shaft 27 which extends forwardly to the head end of the bed. Another driving shaft 28 extends rearwardly to the foot end of the bed, both shafts receiving power from mechanisms contained in a gear box or housing 30.

The drive shafts 27 and 28 are connected respectively with the bed ends at the head and foot of the bed by similar mechanisms and consequently only the connection between the shaft 27 and the stub shaft 24 will be described, as illustrated in FIGS. 2 and 3. The shaft 27 as well as the shaft 28 are both hollow or tubular in form and a short connecting rod or shaft 31 extends into the one end of the hollow shaft 27. The rod or shaft 31 is confined within and driven by the drive shaft 27 by means of a shear pin 32 extending through the rod or shaft 31 and through slots 33 formed in the drive shaft 27. A spring 34 urges the rod or shaft 31 outwardly toward the head of the bed.

The rod or shaft 31 is formed to connect with the stub shaft 24 in any suitable manner. For example, in the construction shown the stub shaft has a transverse slot in the end portion thereof and the shaft 31 has a projection 35 formed to extend into this slot. When it is desired to disconnect the shaft 27 from the stub shaft 24, it is merely necessary to grasp the shear pin 32 and move it into the shaft 27 against the action of the spring 34 to disengage the end of the rod 31 from the stub shaft 24. The sleeve 25 which surrounds the end of the stub shaft 24 serves to confine the rod or shaft 31 in engagement with the stub shaft. As shown in FIG. 2, this connection between the shaft 27 and the stub shaft 24 is preferably covered by means of a guard 36 suitably secured to the adjacent cross member 23 of the bed frame. Another guard or cover member 37 is provided at the foot end of the bed to cover the drive connection between the drive shaft 28 and the 3. stub shaft of the mechanism in the foot end of the bed. Both of the drive shafts 27 and 28 are detachably connected by suitable couplings with shafts extending outwardly from the gear box 30.

The spring frame of the bed may be of any usual construction, that shown being formed of three sections or parts. These sections or parts include a head part 40, foot or leg part 41 and an intermediate part 42, these parts being hingedly connected as shown in FIG. 1, and being movable from the positions in which the three parts of the spring frame are alined, as shown in full lines in FIG. 1, into fully raised positions as shown in broken lines in FIG. 1, or into positions intermediate between the full and broken line positions shown. The sides ofspring sections or parts may be made of angle bars at opposite sides of the bed which are connected with the usual spring mattress, not shown, of any suitable or desired type.

The side frame members of the intermediate parts 42 are secured to extensions 43 pivoted at 44 on upwardly extending posts or supporting columns 45, the lower ends of which are riveted or otherwise secured to the side frames 19 of the bed. The head end spring part is pivoted at 46 to the extensions 43 of the intermediate part and the rear end of the intermediate part is pivoted at 47 to the foot or leg parts 41. The positions of these parts of the spring frame are also under control of the occupant of the bed, as will be hereinafter explained. 49 represents transverse bars which hold the sides of the frame parts 40, 41 and 42 in correct relations to each other.

The raising and lowering of the head part 40 of the spring frame is effected by means of a pair of arms 50 secured at their lower ends to an axle or tube 51 which may oscillate about a fixed axis relative to the side frame members 19. The upper ends of the arms 50 are offset as shown at 52, FIG. 2, to extend under inwardly extending flanges of the side members of the spring frame parts 40 and the ends of these oifset portions may be provided with rollers 53 formed to roll on the under surfaces of the angle bars for swinging part 40 of the spring frame about its pivot 46.

The movement of the arms 50 is effected by rotating the tubular shaft 51, and this is accomplished by means of mechanism contained in a housing tube 54 which is preferably of square cross section and which contains a screw threaded shaft 55 cooperating with a nut 56 slidable in the tube 54, FIGS. 4 and 5. This nut is secured to a pair of bars 57, the forward ends of which are pivotally connected with a pair of rollers 58 mounted to roll within the square housing tube 54. The bars 57 also are pivotally connected to an arm 60 extending out of this square tube 54 through a slot 61 formed in the upper portion thereof. The outer end of this arm is pivotally connected at 62 to one end of another arm 63, the other end of the same being rigidly secured to the tubular axle or shaft 51, this axle being rotatably connected with the housing tube 54 by means of a strap 64, see particularly FIG. 4, the ends of the strap being bolted or otherwise rigidly secured to the tube 54.

In the operation of the mechanism for adjusting the head part 40 of the spring frame, when the screw shaft 55 is rotated, it will move the nut 56 and the bars 57 connected therewith lengthwise into the housing tube in such a manner as to act on the outwardly extending arms 60.

The mechanism is shown in FIGS. 4 and 5 in the position in which the head spring frame 40 is in horizontal position, as shown in full lines in FIG. 1. Consequently rotation of the screw shaft 55 in one direction will cause the bars 57 to exert a pull on the outwardly extending link 60 which is transmitted to the outer end of the arm 63, thus causing the hollow shaft or axle 51 to swing in a clockwise direction in FIG. 4. The axle in turn causes the supporting arms 50, which are secured adjacent to the ends of the axle 51, to swing so that their upper ends swing upwardly and thus cause the sections 50 of the spring arm to swing upwardly about their pivotal connections with the extension 43 of the intermediate spring frame member 42. Consequently the head part 40 of the spring frame member will be swung upwardly. By reversing the direction of rotation of the screw shaft 55, the head part 40 will be swung downwardly.

An advantage of the construction described is that as the threaded shaft 55 turns, and the nut 56 and the bars 57 move lengthwise of the housing 54, force is exerted against the lever 63 to turn axle 51. This pulling force is restrained from exerting a bending force to axle 51, by bearing strap 64, directly connected to the housing tube.

By means of the rollers 58 the bars 57 will remain in parallel relation to the housing tube 54 so that the lever 64 is swung by a straight line pull on the bars 57 and the rollers 58 remaining against the housing will prevent the upward resultant force from binding the nut 56 and screw 55.

The head part 40 of the spring frame is also provided at each side with a downwardly extending leg 65 pivoted thereto at 66 and held by means of springs 67 in positions substantially perpendicular to the part 40. The lower ends of these feet or legs 65 rest on the upper surface of a cross frame member 23 secured to the side frame members 19, when the head part 40 of the spring frame is in horizontal position. It is possible, however, to swing these legs forwardly, for example, by means of a handle 69, so as to permit the part 40 of the spring frame to incline downwardly into a shock position. The handle 69 is in the form of a rod which extends crosswise of the spring frame member 40 and has its ends secured to the legs 65 so by grasping the handle 69 both legs 65 can be swung forwardly at the same time. The ends of the handle member 69 have extensions 70 which will rest upon the cross bar 23 when the spring part 40 is in its fully lowered position and thus prevent further downward swinging of this spring frame part 40.

71 represents cams of approximately triangular shape pivoted at 72 to swing through approximately a right angle 'into position to engage the legs 65 and swing them forwardly out of engagement with the cross frame member 23 when it is desired to move the spring frame part 40 downwardly into shock position. When the frame part 40 is raised from its lowered or shock position, the legs 65 engage the cams 71 and return them to the position shown in FIG. 1.

Suitable mechanism is provided for moving the intermediate frame member 42 into various positions and for this purpose the mechanism is provided within another housing tube 75 of square cross section. This mechanism may be identical with that shown within the housing tube 54 for actuating the head frame part 40 and is therefore not shown in detail. This mechanism includes a nut, also not shown, which through intermediate mechanism actuates a rod 76 extending through a slot in the upper face of the housing tube 75. This rod extends rearwardly and is pivotally connected at 77 with one end of an arm 78, FIGS. 4 and 5, the other end being secured to a hollow axle 79, the opposite ends of which are arranged in suitable bearings in the side frame members 19. The intermediate part of the axle 79 is rotatably held by means of a strap 80 the opposite ends of which are secured to the square housing tube 75. Both shafts 51 and 79 are connected with both tubes 54 and 75.

The hollow axle 79 is provided adjacent to its ends with a pair of arms 83, the outer ends of which are pivoted to links 84 pivoted to the side frame parts of the intermediate spring part 42. Consequently when the link or arm 76 is moved forwardly by means of the screw shaft and nut contained within the housing tube V 75, the intermediate spring part 42 will be swung from The opposite side arms 41 of the leg part of the spring frame are provided at their forward ends with extensions to which the intermediate frame part 42 is pivotally connected at 47 and consequently when the intermediate spring frame part 42 is raised, it Will also raise the forward end of the leg supporting part 41 of the spring frame. The same pivot 47 which forms the connection between the frame parts 41 and 42 also has pivotally connected therewith two bars 87, the lower ends of which are provided with rollers which roll along bottom plates 88 so that the inclination of the leg-supporting spring part 41 varies in accordance with the position of the intermediate spring supporting part 42. However I have provided between the bars 87 and the spring frame part 41 means for further adjusting the inclination of the leg-supporting spring part 41. For this purpose I have provided a plurality of notches 89 in the upper face of the bars 87 and have also provided legs 90 pivoted on the spring frame part 41 at 91 so that the lower ends of these legs 90 may engage in any one of the notches 89, thus providing a ratchet to vary the inclination of the leg-supporting spring part 41. The raising of the leg-supporting spring part 41 to swing it about its pivot 47 is done manually.

The moving of the various parts of the bed into different positions is effected by power supplied by a motor 100, FIGS. 6 and 7. This motor is of the reversible type and has a drive shaft 101 provided with a worm which meshes with a worm gear 102 which is directly connected in any suitable manner with a gear 103. This gear meshes with a second gear 104 hich in turn meshes with a third gear 105 so that when the motor is rotated all three gears are also rotated. The gear 103 is detachably connected by means of a clutch to a stub shaft 107 suitably connected with a shaft arranged in the housing tube 75. The gear 104 is similarly connected with a stub shaft 108 which is connected with the shaft 27 through which the raising and lowering of the bed itself is effected, and the gear 105 is connected by suitable clutch means with a stub shaft 109 which in turn is connected with the screw shaft 55 within the tube 54.

The worm gear 102 has a hub 110 mounted to rotate freely about the stub shaft 107, FIGS. 7 and 8, and this hub has a suitable driving connection (not shown) with a washer or disk 112 secured toa hub 114 formed integral with the gear 103.

Each of the three gears is connected with its stub shaft by means of clutch mechanism such as shown in FIGS. 8-10, and since the clutches for the three stub shafts and gears are identical, only one of these clutches will be described, namely the one connecting the gear 105 with the stub shaft 109. This stub shaft 109 has a portion 115 of enlarged diameter which is provided with a thrust collar 111 which is set on the shaft 115 and rotatably fits into a bore in the gear hub 114, being retained therein by the disk 112. The shaft 115 is provided with a keyway or longitudinally extending slot or groove 115'. On the face of the gear opposite to the hub portion 114 thereof is a key-carrying flanged disk 116 mounted thereon by means of a suitable rivet 117 secured to the gear and extending through slots 117' in the key-carrying disk for guiding this disk for limited movement relatively to the gear and crosswise of the shaft part 115. The key-carrying disk has a key 118 secured thereto and extending into a key-receiving slot 119 in the gear. As the key-carrying disk is moved relatively tothe gear, the key 118 thereof may enter the keyway 115' [formed in the enlarged portion 115 of the shaft. Consequently, when the key-carrying disk is in the position shown in FIG. 8, the key extends partly into the keyway in the shaft 115 and also remains partly in the slot 119 in the gear so as to form a driving connection between the gear and the shaft.

The key 118 is movable into and out of engagement with the keyway in the shaft 115 by shifting of the keycarrying disk 116. This shifting is accomplished by means of a wheel or roller 122 which is mounted on the core 124 of a solenoid 125 so that the wheel or disk 122 may be moved either into the full line or dotted line position shown in FIG. 8. When in the full line position, the roller or wheel 122 will engage an outwardly projecting portion 126 of the flange of the key-carrying disk as the gear and disk rotate 180 degrees about shaft 109. As whee-l 122 rolls over projection 126, the key-carrying disk will be moved toward the shaft 109, and the key 118 will be moved out of the keyway in the shaft. This allows the gear to rotate about shaft 109 without imparting rotation to the shaft. If, however the roller is moved to the broken line position shown in FIG. 8, it engages the projecting part 127 of the key-carrying disk which rotates 180 degrees with the gear. Consequently the key is moved into the keyway in the shaft and the shaft rotates with the gear as shown in FIG. 8.

The key-carrying disk is yieldingly held in either of its two key-supporting positions. As shown in FIG. 10, a pair of coil springs 130 is provided. One end of each spring is connected to a yoke 131 mounted on the rivet 117 secured to the gear 105. The other ends of the springs are secured to posts or projections 134 on the key-carrying disk. Consequently these springs will urge the key-carrying disk toward the position shown in FIG. 8, in which the key 118 is in the keyway 115 of the enlarged portion 115 of the shaft 109. However, when the projecting part 126 of the flange of the key-carrying disk is pushed toward the axis of the shaft by means of the roller 122, the key is moved out of its keyway and the springs 130 are placed under tension.

In order to yieldingly hold the key-carrying disk in the position in which the key 118 is out of the keyway, a detent is provided which, in the construction shown in FIG. 12, is in the form of a ball 137 located in a hole in the gear 105 and urged outwardly by a spring 138 also located in the hole of the gear. This spring urges the ball 137 into a notch or depression 139 formed in the key-carrying disk 116. Consequently by means of this detent the key-carrying disk will be yieldingly held in a position in which the key is out of engagement with the shaft 109 until the key-carrying disk is forced out of the yieldingly held position by the engagement of wheel 122.

It is of course also very desirable to provide limit switches which will limit the movement of each of the shafts 107, 108 and 109 to prevent movement of the spring frame parts 40, 41 and 42 beyond certain predetermined positions. For this purpose there is provided attached to the gear housing 30, a second housing 140 in which the solenoids 125 are arranged and through which each of these shafts extends. The shafts are provided in the portion thereof within the second housing 140 with screw threads 141, and a pair of nuts 142 and 143 made of insulating material are provided on the threaded portion of each shaft to ride lengthwise thereof when held against rotation. The nut 143 is positioned to engage a movable electric contact member 145 when moved to the desired limit to the right in FIG. 8, thus breaking a circuit between this spring contact member 145 and a stationary contact member 146. Similarly when the other nut 142 moves to the desired limit to the left in FIG. 8, it will engage a movable contact member 147 to break a circuit between this member and a stationary current-carrying member 148.

It is also desirable to make the two nuts 142 and 143 adjustable on the screw threaded part of the shaft 115 so that the extent to which the various spring parts of the bed may be moved may be varied. For this purpose, as shown in FIG. 11, these nuts have outwardly extending flanges 150 provided at intervals with notches 151 into which a stationary blade 152 may enter. This blade may be secured to the wall of the gear case 30. This blade may enter into any of the notches or recesses 151 in the flanges 150 to hold the nuts against turning, and it may also be moved out of the notches to permit the nuts to be turned manually relatively to the threaded portions 141 of the shaft so that the extent of movement of the parts of the spring frame of the bed, or of the raising and lowering of the bed may be limited as desired.

It is also desirous to provide means by which any of the shafts 107, and 109 may be turned manually to make the adjustments controlled thereby in the event of a power failure. For this purpose the enlarged portions 115 of these shafts are made hollow and the outer end of the shaft 115 is notched or bifurcated at 155. The hollow portion of the shaft terminates at its inner end in a smaller bore.

Special cranks are provided to cooperate with either of the shafts 107 or 109; the crank which is shown in FIG. 2 is in inoperative or storage position and is provided with an elongated shank 160 having a handle 161 at one end thereof and having an extension of smaller diameter 162 at the other end of the shank 160. This crank may be inserted into the bore of the shaft 115, as clearly shown in FIG. 9, so that the shank portion 160 enters into the larger portion of the bore of this shaft. The crank is also provided with a transversely extending pin 163 formed to enter into the slotted outer end of the shaft 115. The crank however cannot turn the shaft 115 to adjust the bed part manually if the key 118 is in the keyway in the shaft 115. However, means are provided for dislodging the key from this position, and for this purpose a slide 164 is provided in this recess or key portion of the enlarged portion 115 of the shaft. This slide has an inclined face formed at one end to engage the key 118 when in the keyway 115 and a rod extension at the other end to move the key out of the keyway. This slide is engaged by the reduced extension 162 of the crank. A spring 167 is provided in a central bore of the shaft which bears against the slide 164 and urges the same into a normal position out of engagement with the key 118 so as to permit the key to move into the keyway in the shaft. For convenience the crank, when not in use, is preferably supported on a pair of cross bars of the bed frame, as shown in FIG. 2.

The three stub shafts extending outwardly from the gear box 30 may be connected with the two screw shafts and with the central shaft 27 in any desired manner. In the construction shown, these stub shafts 107 and 109 extend into tubular shafts 170 and 171 and are slidably, to a limited extent, secured thereto by means of shear pins 173 in the form of rivets. In the case of the central shaft 27, which effects the raising and lowering of the bed, the stub shaft 108 has a pin extending into a bifurcated coupling 172 secured to the shaft 27.

The tubular shafts 170 and 171 are pinned or rigidly secured to end portions of smaller diameter of the screw shafts in the housing tubes 54 and 75 by means such as hardened drive pins 178. These smaller ends of the screw shafts extend through a safety plate 174 arranged transversely of the bed and are slidably held in place on the reduced ends of the screw shafts 55 and the larger tubular shafts 170 and 171. A channel shaped cover 176 fits over the shafts 27, 170 and 171, the bottom being closed by a plate 175.

By connecting the tubular shafts 170 and 171 to the shafts 107 and 109 by means of shear pins 173, any obstruction which would prevent the spring parts of the bed from being raised or lowered will cause the shear pins to break and thus prevent damage to the drive mechanism. It is of course also necessary in the event that a shear pin breaks to prevent the parts of the bed which are normally driven by the shear pin and their thrust supported by the shear pin from sliding forward in the-event a shear pin breaks, thus causing the spring frame head or foot section to drop with possible injury to the patient. For this purpose the tubular shafts and 171 are of larger diameter than the holes in the safety plate 174 through which the small ends of the screw shafts pass and the screw shafts within the housing tubes 54 and 75 can only move until the tubular shafts engage the safety plate. The limited slidable connection of the shear pins 173 permits reverse thrust, when this occurs, to be taken directly by the shafts 170 and 171 bearing against the bearing hubs of gear box 30.

During the normal actuation of the spring frame members of the bed, force will be exerted on the shafts 170 and 1'71 in a direction toward the head of the bed, and this force is resisted by means of thrust collars 180 positioned between the gear box 30 and the gears 103, 104 and 105. Since the gear box is firmly mounted on the cross frame member 23 and another cross frame member 181, the forces exerted through the thrust washers on the gear box will be amply resisted.

One of the features of this invention is to provide the patient occupying the bed with controls whereby he can shift the sections of the spring frame to suit his comfort or convenience and also, if desired, to raise and lower the bed. For this purpose control devices or hand switch members are provided, FIGS. 2 and 13, which have contacts for closing circuits to effect various operations of the bed. For example, the switch member 190 has a series of button areas 191, each of which has an index thereon to guide the user as to which button to press to obtain the desired result for shifting the bed parts. At times it may be desired not to provide the patient with any means for moving the bed up and down because of the danger of having a patient fall out of bed while in raised position, and if this is desired another control device 192 may be provided which has four contact buttons marked as in FIG. 14.

The hand switch members 190, 192 are preferably made of soft, molded rubber or similar soft material and the button areas indicated at 191 are thin membranes molded intergral with the main body and located over the buttons of the switch member so as to enclose the electrical switches completely from the surrounding atmosphere.

In the electrical diagram shown in FIG. 15, the various electrical components are shown with the hand switch 190 plugged into the socket 201, while the hand switch 192 is shown unconnected in FIG. 16. The indicia used in FIGS. 6, 13 and 14 has been abbreviated in the circuit diagrams to simplify and conserve space. The following are representative abbreviations: Head UpHU; Head DownHD; Foot UpFU; Foot Down- FD; Bed UpBU; Bed DownBD; and Down-- DWN.

To facilitate the use of either of the switch members 190 or 192 and make it possible to exchange one for the other, the cords of these units are provided at their ends with identical plugs 195. A control box 200 is provided at the foot end of the bed and is mounted on one of the cross members 23. This control box has a socket 201 to receive either of the plugs 195 to make the proper circuit connections to the electrical system. The control box has a cable 202 housing the necessary wires, which ends in another plug and socket connection 204 which also has a cord and plug 205 for connection to a power outlet. This socket 204 is mounted on the gear box 30 and housing 140 containing the drive motor 100 and the limit switches 145, 146, 147 and 148. With this arrangement of removable connectors and cables, it is possible to remove and replace either mechanical or electrical units individually without having to remove all of the equipment, thus cutting down time of the bed for repairs, and also making it possible to change the switch members 190 and 192 for the class of patient using the bed.

Referring now to the circuit diagram of FIG. 15, the dotted line enclosure 190 indicates the switch member having up and down switches for the Head, the Foot and the Bed. The dotted line enclosure 200 indicates the control box outer casing, this control box being divided by a mechanical barrier or wall 208. The dotted line enclosure 210 represents an enclosure of insulating material for the up and down relays 212 to keep their switch elements 214, 216, 218, 220, 222 and 224 free from foreign matter and isolated from other circuit wires. The windings of the electromagnets of these relays 212 are located below the barrier 208 while their switch elements are located above the barrier 208, with the electromagnetic cores projecting through openings in the barrier 208.

A transformer 226 has one part of its electromagnetic core 227 above the barrier 208 and another smaller part below the barrier 208. The part of the transformer 226 above the barrier has an auto transformer winding 228 providing a low voltage section incorporated in a rectifier circuit indicated generally at 230, which supplies filtered direct current for operation of the UP relay 232 and the DOWN relay 234 for controlling the rotation of the drive motor 100. Rectifier 230 also provides current to the shift solenoids 125.

The part of the transformer core below the barrier 208 has a winding and rectifier circuit 236 which supplies direct current of very low voltage and low amperage to operate the relays 212 through operation of the switches of the switch members 190 or 192. It should be noted that this rectifier does not include a filter condenser, the lack of which further reduces arcing at the contacts.

At the left hand side of the control box 200 are located three switches 238, 240 and 242 which connect the HEAD, FOOT and BED circuits to current to make them operative or to cut them oif from current and make them inoperative, as is shown in FIG. 6 by the indicia opposite each switch.

Operation As shown in FIG. 15, negative current from the rectifier 236 is supplied to all of the switches HD, FD, BD, BU, FU and H through the line 244, which as shown are in their normally closed circuit position as far as their series connection to each other is concerned. This series connection assures that only one operation can take place at a time. For instance, neither the HEAD, FOOT or BED can go up and down at the same time.

Let us assume that we want the HEAD UP position. By depressing switch HU negative current from line 244 fiows through the top contact of HU190 to the line 248 which is connected to the HU unit of the relays 212. Current then flows through this relay to the line 258 through the HEAD switch 238, line 260, back to the positive terminal of the rectifier 236, completing the circuit. Thus the HU relay 212 is energized and its switch 216 closes. Current of negative polarity then fiows from rectifier 230 through line 262, HEAD solenoid 125 contacts 148, 147, line 264, switch 216, line 266 to the UP relay 232, line 266 to the positive side of the rectifier 230, completing the circuit. Thus the HEAD solenoid 125 is energized pulling its roller 22 into the dotted line position of FIG. 8. UP relay 232 is also energized to close its contacts 268 and provide current from the 205' side of the current supply line through line 272, contact 274, line 276, contacts 268, contact 278 and lines 280 and 282 to the motor 100 with its line 285 connecting it to the other side 205" of the current supply line 205. The motor 100 is thus energized to rotate the gears 103, 104 and 105 and the key carrying, flanged disk 116 on the gear 105, causing it to engage the roller 22 (dotted line position FIG. 8) and thus throw its key 118 into driving position to cause the HEAD end of the bed to rise.

The HEAD end will continue to rise if the HU190 switch is held depressed until the nut 142 on the threaded portion 141 of HEAD shaft 109 engages the switch finger 147 and breaks the circuit between it and contact 148, whereupon through the circuitry just explained the motor UP relay 232 is deenergized and the motor is stopped. Any elevation between the extremes of up and down may be had by releasing the HU190 switch when desired.

To lower the HEAD end the switch HD190 is depressed, this then provides negative current from the line 244 to line 246, HD unit of relays 212, line 258 HEAD switch 238, line 260 back to the positive side of the rectifier 236, thus completing the circuit. Since the switch 214 of the HD relay is now closed, negative current now flows from rectifier 230, line 262, the HEAD solenoid 125, limit contacts 146, 145, line 284, closed switch 214, line 286 down relay 234, line 266 .to the positive side of the rectifier 230, thus closing contacts 228 and 290 to permit current from the 205' side of the current supply line 205 line 272, contact 288, motor 100 and line 285 to the other side 205" of the line. This energizes motor 100 to rotate in a down direction and since HEAD solenoid 125 is also energized the roller 22 will again push the key 118 into driving connection between the gear and shaft 109. The HEAD end will now descend to the position desired by releasing the H-Dl90 switch or if it is held depressed the HEAD end will descend until the limit contacts 145, 146 break the circuit and stop the motor 100.

If the HEAD switch 238 is not in its on position neither up or down operation of the HEAD end could take place since the current supply to the related parts is cut oil. Current for the FD, FU units of switch relays 21 flows from these relays through line 259 to FOOT switch 240, line 260 to the positive side of the rectifier 236. While switches 238 and 240 are on Off, single pole single throw switches, the BED switch 242 is a two pole, three position switch but used and wired as an on, oif switch when used with hand switch 190. This is accomplished by leaving line 253 of the upper contact of switch 242 isolated by reason of the fact that the plug 195 of hand switch 190 does not have a plug prong connecting to it while the lower contact of switch 242 connects the line 257 to the line 260 and the positive side of the rectifier 236. Also line 257 connects to the 201 where the plug 195 connects it by a jumper 257' to the line 255 which returns to the lower end of the BD unit of switch relays 212, thus connecting both BD and EU switch relays 212 to the line 260 through the switch 242.

Operation of any of the switches FU, FD, BU and BD will cause a similar sequence of current flow and operation of the proper relay 212, solenoid and the UP or DOWN relays 232 and 234 to make the mechanical drive function as desired. Switches 240 and 242 of course must be in on position for these operations.

An indicator light 290 is provided as a cautioning means to indicate when the BED position is at any elevation higher than bottom so that a night nurse will lower the patient to prevent the falling out of bed at higher than the lowest BED position. This is accomplished by the addition of the switch 292 which operates in unison with the limit contacts and 146, that is when the limit contact finger 145 is in open position by the engagement of insulated nut 143 with it; the nut 143 also engages the finger of switch 292 and opens its contacts. This means that alternating current from the lower end of transformer winding 228 and line 205" is not supplied to the indicator lamp 290 back to the positive lead of the rectifier 230 where it connects with the winding 228 except when the bed is in some UP position, whereupon contacts 292 would be in closed position.

When it is undesirable for the patient to be able to raise or lower the bed, the switch member 192 would be plugged into the socket 201 in place of the switch member 190 just described. When the unit 192 is plugged in, the indicia located at the switch is not used but the indicia within the frame 300 is then used, this by the fact that when the hand switch 192 is plugged into the socket 201 it makes some different connections than the hand switch 190.

As will be noted in FIG. 16, the lines from the switches HU, HD, FU and FD are connected to the lines 244, 246, 248, 250 and 252, the same as is used when hand switch 190 is plugged in. Therefore, these switches and the circuitry connected therewith operate the same as already explained. Since hand switch 192 does not have BU or BD positions, the switch 242 is availed of to provide these by circuitry which will now be explained.

The plug 195 of the hand switch 192 has a jumper 302 and a line 304 which also acts as a jumper. The jumper 302 connects the previously isolated line 253 to the line 255 while the line 304 connects the lines 254 and 256. Thus, when the switch 242 is thrown to its up position, see also UP indicia in frame 300, FIG. 6, the positive line 260 from rectifier 236 is connected through the switch 242 to the line 257 of the BU relay switch 212 and the line 257 connecting to the socket 201 is now isolated. Since current flows from the negative side of the rectifier 236 through line 244 into the hand switch 192 and through its series connections through the lower contacts of the switches HD, FD, HU and FU to the line 304 and then the lines 254 and 256, the BU switch relay 212 will be energized and cause the bed to move up as previously explained. If switch 242 is moved to its middle position (OFF in frame 300) no current is supplied to either BD or BU relay switches 212. If switch 242 is moved to its down position (DWN in frame 300) current will flow from rectifier 236, line 244 lower contacts HD, FD, HU and FU of hand switch 192, line 304 and line 254, BD unit of relay switch 212, line 255, jumper 302 to line 253, switch 242 to line 260 and the other side of the rectifier completing the circuit and causing the bed to lower.

From the above it can be seen that the invention provides versatile bed movements to positions conducive to the comfort of a patient at his will without outside help of a nurse or strain on the patient, while at the same time certain movements of the bed may be denied the patient to maintain a low bed height accompanied by a signal device to indicate a bed height adverse to that wanted.

As previously mentioned, a low voltage, low amperage power supply of the order of 14 volts at 15 milliamperes is supplied to the hand switch 190 or 192. This voltage and amperage is that low and safe that the UL. Underwriters have approved this device to be used with the hand switch 190 or 192 in an oxygent half tent covering a patient. The barrier 208 effectively prevents the higher voltage, higher amperage wires of the heavier work accomplishing components from coming into contact with hand switch 190, 192 circuits which if connected to higher voltage and amperage would cause explosion in a high oxygen content atmosphere. I

It will be understood that various changes in the detials, materials and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. A bed having a bed frame, means for raising and lowering said bed frame, a spring frame mounted on said bed frame and comprising a head part and a foot part, an intermediate part hingedly connected with said head part and said foot part, independent mechanisms mounted on said bed frame for swinging said head'part and intermediate part into different angular positions relatively to each other, each of said mechanisms including a shaft 12 extending lengthwise of said bed frame, a safety plate through which said shafts extend and parts on said shafts in abutting relation to said safety plate for stopping longitudinal movement of said shafts.

2. A bed having a bed frame, a spring frame mounted on said bed frame and comprising a plurality of parts hingedly connected, means for shifting said hingedly connected parts relatively to each other into different angular positions and each including a shaft extending lengthwise of said bed frame, a gear housing containing mechanism connected with said shafts for rotating the same, a safety plate mounted on said bed frame and extending crosswise thereof and through which said shafts extend, said safety plate being arranged in spaced relation to said gear housing, said shafts being made of separate parts connected by shear pins located on said shafts between said gear housing and said safety plate, and stop parts on said shafts arranged to engage with said safety plate in the event that a shear pin breaks.

3. A bed according to claim 2 and including a third shaft mounted on said bed frame and effecting the raising and lowering of the bed, said third shaft also extending through said saftey plate, a shear pin, and a driving shaft connected with said third shaft by said shear pin.

4. A bed having a bed frame, a spring frame mounted on said bed frame and comprising a plurality of parts hingedly connected with each other, shafts connected with said spring parts for swinging the same relatively to each other and also mounted on said bed frame, a gear housing containing gears for rotating said shafts, a motor for driving said gears, and thrust washers interposed between said shafts and said gear housing for opposing axial movement of said shafts in one direction, a plate mounted on said bed and extending crosswise of said bed and having holes through which said shafts pass, and stop means positioned on said shafts to oppose movement of said shafts in the opposite direction.

5. A bed having a bed frame, mechanism for raising and lowering the bed frame including the driven shaft extending lengthwise of the bed frame, a spring frame mounted on said bed frame and formed of a plurality of parts hingedly connected with each other, means for moving said hinged parts into different inclined positions and including a driven screw shaft for each of said adjustable spring parts and cooperating with a nut, a gear housing mounted on said bed frame and containing gearing terminating in stub shafts extending out of said housing, a motor for driving said gearing to rotate said stub shafts, one stub shaft being provided for each of said driven shafts mounted on said bed frame, and connections between each stub shaft and a driven shaft, each of said connections including a hollow shaft, a shear pin connecting each stub shaft with its hollow shaft, and means for holding each driven shaft against lengthwise movement in the event that its shear pin breaks.

6. A bed accord-ing to claim 5, in which said means for holding each driven shaft against lengthwise movement includes a rigid connection between said hollow shaft and its driven shaft, a safety plate extending crosswise of said bed and rigidly secured thereto and provided with holes therein through which said driven shafts pass, said hollow shafts each being arranged with one end thereof in close proximity to said safety plate to engage said safety plate if said shear pin breaks, and thrust washers arranged between the other ends of said hollow shafts and said gear housing to limit the movement of said driven shafts in either direction.

7. A bed having a bed frame and a spring frame mounted thereon and made in sections pivotal-1y connected with each other for swinging into various inclined positions, power actuated means for moving said sections relatively to each other including a screw shaft, a nut cooperating with said screw shaft, a horizontal tubular housing secured to said bed frame and in which said screw shaft and nut are arranged, rollers in said housing and of a diameter substantially equal to the internal dimension of said housing and connected to said nut to guide the same in said housing, a transverse shaft pivoted on said bed frame, an arm extending outwardly from said transverse shaft and rigidly secured thereto, a link extending out of said housing and having one end thereof pivoted to said arm and the other end connected with said nut and moved lengthwise of said housing by said nut to swing said arm and said transverse shaft, arms on the ends of said shaft and engaging a spring section for raising and lowering the same when said transverse shaft is rotated, means for rotatab ly connecting said transverse shaft with said housing to restrain said housing against endwise movement relatively to said bed frame, and a motor for imparting rotary motion to said screw shaft.

8. A bed construction according to claim 7 and including bars in said housing interposed between said nut and said arm.

9. A bed having a bed frame, a spring frame mounted on said bed frame and comprising a head part and a foot part, an intermediate part hingedly connected with said head part and said foot part, mechanisms mounted on said bed frame for swinging said head part and intermediate part relatively to each other, each of said mechanisms including linkage connected with one of said spring parts for swinging the same when said linkage is shifted, a longitudinally extending drive shaft, a screw and nut connection between said shaft and said linkage for shifting the same, a reversible motor, a gear box containing mechanism interposed between said motor and said screw and nut connection for establishing a drive connection between said motor and said screw shaft, a controller containing switches and conductors which control the direction of rotation of said motor and which actuate said interposed mechanism for driving said shaft, a protective rigid tubular housing substantially surrounding said shaft, said housing being rigidly connected to said gear box, and a thrust collar in said gear box which takes longitudinal forces exerted by said shaft for preventing distortion of said bed frame by said forces.

10. A bed having a bed frame, a spring frame mounted on said bed frame and comprising a head part and a foot part, an intermediate part hingedly connected with said head part and said foot part, mechanisms mounted on said bed frame for swinging said head part and intermediate part relatively to each other, each of said mechanisms including a screw shaft mounted on said bed frame against axial movement, a nut movable lengthwise of said shaft when the same is turned, linkage connected with said nut and one of said spring parts for swinging the same when said linkage is shifted by said nut, a reversible motor, a gear box containing mechanism interposed between said motor and said screw shaft for establishing a drive connection between said motor and said screw shaft, a controller containing switches, electrical connections actuated by said switches for controlling the direction of rotation of said motor and for actuating said interposed mechanism for driving said shaft, a protective rigid tubular housing substantially surrounding said shaft,

said housing being rigidly connected to said gear box, and a thrust collar in said gear box which takes longitudinal forces exerted by said shaft for preventing distortion of said bed frame by said forces.

11. A bed having a bed frame, a spring frame mounted on said bed frame and comprising a head part and a foot part, an intermediate part hingedly connected with the head part and said foot part, mechanisms mounted on said bed frame for swinging said head part and intermediate part independently of each other, each of said mechanisms including linkage connected with one of said spring parts for swinging the same when said linkage is shifted, :a longitudinally extending drive shaft, a screw and nut connection between said shaft and said linkage for shifting the same, a reversible motor, a gear box containing mechanism interposed between said motor and said screw and nut connection for establishing a drive connection between said motor and said screw shaft, a controller containing switches and conductors which control the direction of rotation of said motor and which actuates said interposed mechanism for driving said shaft, a protective rigid tubular housing substantially surrounding said shaft, said housing rigidly connected to driving means, and a thrust bearing for the driven end of said gear shaft fixed to said housing, said housing and the rigid connection to the driving means balancing the forces exerted by said shaft for preventing distortion of said bed frame by said forces, a shaft forming a part of said screw and nut connection, and a clutch forming a part of said interposed mechanism and actuated by said controller for connecting and disconnecting said shaft with said motor.

References Cited by the Examiner UNITED STATES PATENTS 1,573,530 2/26 Weaver 569 1,711,534 5/29 King 340278 1,906,247 5/33 Buff 198-213 2,297,105 9/42 Laukhuff 569 2,344,397 3/44 Drexler et al. 428 2,481,477 9/49 Peery 74-428.8 2,560,465 7/51 McVicker et al. 569 2,572,521 10/51 Rogers 340278 2,582,565 1/52 Schnippel et al. 568 X 2,670,476 3/54 Travis 566 2,741,092 4/56 Marshall 569 X 2,784,395 3/57 Gorby 340-282 2,843,240 7/58 Kruse 568 2,912,704 11/59 Burst 563 X 2,913,300 11/59 Darnell et :al. 563 X 2,947,856 8/60 Fox 74105 X 3,050,744 8/62 Mann et a1. 563

FOREIGN PATENTS 9,807 1902 Great Britain. 640,791 7/50 Great Britain.

FRANK B. SHERRY, Primary Examiner. GEORGE L. BREHM, Examiner. 

1. A BED HAVING AS BED FRAME, AS MEANS FOR RAISING AND LOWERING SAID BED FRAME, A SPRING FRAME MOUNTED ON SAID BED FRAME AND COMPRISING A HEAD PART AND A FOOT PART, AN INTERMEDIATE PART HINGEDLY CONNECTED WITH SAID HEAD PART AND SAID FOOT PART, INDEPENDENT MECHANISMS MOUNTED ON SAID BED FRAME FOR SWINGING SAID HEAD PART AND INTERMEDIATE PART INTO DIFFERENT ANGULAR POSITIONS RELATIVE TO EACH OTHER, EACH OF SAID MECHANISMS INCLUDING A SHAFT EXTENDING LENGTHWISE OF SAID BED FRAME, A SAFETY PLATE THROUGH WHICH SAID SHAFTS EXTEND AND PARTS ON SAID SHAFTS IN ABUTTING RELATION TO SAID SAFETY PLATE FOR STOPPING LONGITUDINAL MOVEMENT OF SAID SHAFTS. 